NAS 5GS refactor
The goal of this MR is to reorganize the NR NAS code into:
- enc/dec library functions (5GS, 5GMM, 5GSM, NR_NAS_defs.h,
nr_fgs_nas_lib.c)
- handlers and callbacks (nr_nas_msg.c)
The following changes are introduced:
1. migrate 5GS enc/dec lib (5GMM and 5GSM) to a dedicated folder
2. add a nested CMakeLists structure
3. refactor NR NAS enc/dec functions
4. refactor NR NAS messages struct definitions
5. remove most of dependency from NAS LTE
6. further refactor of PDU Session Establishment Accept processing to
separate enc/dec from handling
7. made naming of 5GS definitions consistent whenever necessary
8. cleanup unused code
9. remove redundant struct definitions
Also:
1. fix decoding of AMF Set ID in 5G-S-TMSI UE identity
2. replace Byte_t directly with uint8_t
Robert Schmidt
e0865421b9